Rotor Master
#1

I've decided to make a stand alone thread for this...
Youtube video with instructions:
https://www.youtube.com/watch?v=0xb_N9yZejc&t=37s
I have been working on my own design for a gauss meter for spec racing rotors. I say spec because it can only measure up to about 1850 gauss. Well, I can make one that will measure up to 4000, but it is a bit more sensitive around zero.
This is based on the ATmega 328p mcu that the Arduino Uno uses. I also am using an external 12 bit adc to get better resolution for the readings, since the arduino has a 10 bit adc. I designed the schematic and the pcb using KiCad, the case is 3d printed and designed in Fusion 360. I am using an arduino sketch for the programming. In theory, someone handy in soldering surface mount components could build one of these based of my designs, which is completely fine.
It works pretty much like the other units on the market. Place the rotor on the holder and spin it to get your readings. I am using 3 sensors to get readings, the middle sensor is the sensor that you should record. The first and the third sensor are there for you to center the rotor. Shim the end of the rotor until you get the 1st sensor and 3rd sensor close in readings at the max value, this will get the middle sensor in the middle of the rotor.
The Rotor Master can be powered off a 2s or 3s lipo or 12v DC power supply. It comes with an XT60 connector on it as a hardware reverse polarity protection. There is no internal circuitry for reverse polarity protection. I probably will add this in the future. Each unit is assembled by hand (mine, lol). I use an accurate bench top dmm to measure each sensor to get the most accurate build that I can. I then calibrate it to a Trinity certified rotor readings.
For anyone who wants to make one themselves, I will provide the schematics, pcb designs, bom, stl, and sketch files needed to make one. I'll get them all into a github repository if there is any interest in it. But making one yourself will require an accurate dmm, an arduino Uno to burn the bootloader on to the bare 328p mcu and then to program it via the rx/tx pins that are broke out.
github repo: https://github.com/trilerian/Rotor-Master
Anyway, here are some pics of the schematic, and pcb design. And then the progress of designing. Enjoy!

Schematic

PCB

Proof of concept


Top view of POF

I ordered 20 PCBs!

Getting ready to build!

All the smb stuff soldered on.

And then the through hole components

The finished product!
Youtube video with instructions:
https://www.youtube.com/watch?v=0xb_N9yZejc&t=37s
I have been working on my own design for a gauss meter for spec racing rotors. I say spec because it can only measure up to about 1850 gauss. Well, I can make one that will measure up to 4000, but it is a bit more sensitive around zero.
This is based on the ATmega 328p mcu that the Arduino Uno uses. I also am using an external 12 bit adc to get better resolution for the readings, since the arduino has a 10 bit adc. I designed the schematic and the pcb using KiCad, the case is 3d printed and designed in Fusion 360. I am using an arduino sketch for the programming. In theory, someone handy in soldering surface mount components could build one of these based of my designs, which is completely fine.
It works pretty much like the other units on the market. Place the rotor on the holder and spin it to get your readings. I am using 3 sensors to get readings, the middle sensor is the sensor that you should record. The first and the third sensor are there for you to center the rotor. Shim the end of the rotor until you get the 1st sensor and 3rd sensor close in readings at the max value, this will get the middle sensor in the middle of the rotor.
The Rotor Master can be powered off a 2s or 3s lipo or 12v DC power supply. It comes with an XT60 connector on it as a hardware reverse polarity protection. There is no internal circuitry for reverse polarity protection. I probably will add this in the future. Each unit is assembled by hand (mine, lol). I use an accurate bench top dmm to measure each sensor to get the most accurate build that I can. I then calibrate it to a Trinity certified rotor readings.
For anyone who wants to make one themselves, I will provide the schematics, pcb designs, bom, stl, and sketch files needed to make one. I'll get them all into a github repository if there is any interest in it. But making one yourself will require an accurate dmm, an arduino Uno to burn the bootloader on to the bare 328p mcu and then to program it via the rx/tx pins that are broke out.
github repo: https://github.com/trilerian/Rotor-Master
Anyway, here are some pics of the schematic, and pcb design. And then the progress of designing. Enjoy!

Schematic

PCB

Proof of concept


Top view of POF

I ordered 20 PCBs!

Getting ready to build!

All the smb stuff soldered on.

And then the through hole components

The finished product!
Last edited by trilerian; 08-27-2023 at 02:49 PM.
#6
Tech Apprentice

this is what I like about the hobby....not necessarily winning races, but the fun stuff relating to improving the equipment. I'm too old to be competitive, so I can have a good time building things
#8

Here’s the Amazon link to the case pictyfor anyone that purchases/builds one.
https://www.amazon.com/dp/B07QRFX94D...p_mob_ap_share
https://www.amazon.com/dp/B07QRFX94D...p_mob_ap_share
#10

Here is the link to my github repository.
It has:
Bill of Materials
Gerber Files for the PCB - these will work for JLCPCB I don't know about any other manufacturers
STL for the case
Sketch for the programming
https://github.com/trilerian/Rotor-Master
This project would cost somebody appx $165 after taxes and shipping, plus you would need to print the case. But that price is if you need to buy an Arduino Uno, breadboard, and stuff for that.
You will still need a digital multi meter. You would have some extra parts as some of the items are bought in multiples. If you price everything out per part and total it after tax and shipping it is about $35 per unit.
It has:
Bill of Materials
Gerber Files for the PCB - these will work for JLCPCB I don't know about any other manufacturers
STL for the case
Sketch for the programming
https://github.com/trilerian/Rotor-Master
This project would cost somebody appx $165 after taxes and shipping, plus you would need to print the case. But that price is if you need to buy an Arduino Uno, breadboard, and stuff for that.
You will still need a digital multi meter. You would have some extra parts as some of the items are bought in multiples. If you price everything out per part and total it after tax and shipping it is about $35 per unit.
#12

This is really cool. I'd build one but I dont want to buy whatever you need to flash stuff, unless its super cheap. Though if you flashed it I'd buy it and the PCB and assemble it myself.
Also I'd say you need to be able to measure rotors that get up to about 2200-2500 gauss, as stock is definitly headed there. I think some of the strongest 13mm mod rotors can get to 2000 if not 2200.
But you have a stack of PCBs, are you not planning on selling them at least?
Also I'd say you need to be able to measure rotors that get up to about 2200-2500 gauss, as stock is definitly headed there. I think some of the strongest 13mm mod rotors can get to 2000 if not 2200.
But you have a stack of PCBs, are you not planning on selling them at least?
#14

This is really cool. I'd build one but I dont want to buy whatever you need to flash stuff, unless its super cheap. Though if you flashed it I'd buy it and the PCB and assemble it myself.
Also I'd say you need to be able to measure rotors that get up to about 2200-2500 gauss, as stock is definitly headed there. I think some of the strongest 13mm mod rotors can get to 2000 if not 2200.
But you have a stack of PCBs, are you not planning on selling them at least?
Also I'd say you need to be able to measure rotors that get up to about 2200-2500 gauss, as stock is definitly headed there. I think some of the strongest 13mm mod rotors can get to 2000 if not 2200.
But you have a stack of PCBs, are you not planning on selling them at least?
As to a kit so to speak, maybe. I can burn the bootloader onto the mcu and put the sketch on it, but it really needs to be fine tuned after all the components are on the board. There are a lot of variables in my sketch that you change based on the quiescent output voltage of the sensors, the output of the 5v regulator, the "zero" output of the adc, and finally the multiplier to get your final gauss numbers.
#15

This is really cool. I'd build one but I dont want to buy whatever you need to flash stuff, unless its super cheap. Though if you flashed it I'd buy it and the PCB and assemble it myself.
Also I'd say you need to be able to measure rotors that get up to about 2200-2500 gauss, as stock is definitly headed there. I think some of the strongest 13mm mod rotors can get to 2000 if not 2200.
But you have a stack of PCBs, are you not planning on selling them at least?
Also I'd say you need to be able to measure rotors that get up to about 2200-2500 gauss, as stock is definitly headed there. I think some of the strongest 13mm mod rotors can get to 2000 if not 2200.
But you have a stack of PCBs, are you not planning on selling them at least?